Sri Sathya Sai Speaks, Vol 23 (1990)
Topic - Excerpt from Divine Discourse
What the Avatars mean

According to numerology, the three letters "Si", "va" and "Raa" make up eleven ("Si"=5, "Va"=4 and "Raa"=2). These eleven are known as the Ekaadas Rudras, the eleven Rudras. The fourth syllable "thri" means "three". Thus Sivarathri is the day devoted to overcoming the eleven Rudras by adoring the Supreme Lord, who is master of them all. The Rudras turn the Buddhi (intellect) towards sensuous objects and thrust the individual in the sea of Samsara (worldly life). The Paramatma (Supreme Spirit) is master of all the Rudras. Only the man who has conquered the eleven Rudras can expect to realise the Supreme. Who are the eleven Rudras? They are the five Karmendriyas (organs of action) the five Jnanedriyas (organs of perception) and the Buddhi. Man must seek to control as much as possible these eleven organs.